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Cellulose-containing waste from the agricultural industry modified by chemical methods is capable of adsorbing metal ions no worse than industrial sorbents (ion exchangers, activated carbons, zeolites, etc.). A wide range of methods for modifying plant raw materials makes it possible to obtain effective sorbents that are environmentally friendly and biologically inert. Proposed technologies of lignocellulosic sorbent manufacturing are highly economically feasible and, additionally, eco-friendly, because they ensure the proper utilization of agricultural wastes, which are very widespread in Ukraine.

The main direction of the industrial development of Ukraine is the solving of the environmental pollution problems under the conditions of preservation of natural resources through complex use of raw materials with involvement of industrial wastes. The developed technology is intended for galvanic, accumulator, machine-building, mine and other enterprises, the wastewater from which contains ions of heavy metals. Heavy metal ions are extremely dangerous toxic substances because of a cumulative effect on aquatic organisms. In order to remove copper ions from aqueous solutions, the chemical precipitation with lime is used. The choice of reagent is associated with its cheapness. The most effective reagent precipitation of copper ions in the form of hydroxide occurs when the pH is raised to 10. In this work, the influence of sludge, which is formed as a result of water purification from copper ions, on the properties of cement was investigated. The effect was evaluated on the following properties: normal density of cement, hardening time, compressive strength at the age of 2 and 28 days and water separation coefficient. This allowed us to develop effective ways to their disposal. The developed method provides: a high degree of metal removal (up to 98-99%); simplicity of technological process; small capital and operating costs; complex technology of wastewater treatment process. Thus, the results of the study will contribute to the creation of low-waste and non-waste technologies for waste processing and disposal.

Iron is one of the most common components in water that adversely affect humans, other living organisms and parameters of water bodies. Therefore, during using and consuming natural waters, and discharging sewage into surface water bodies, it is necessary to remove iron compounds from the aquatic environment. The use of capillary materials in water purification processes is a promising area of research. Experimental data proved the high efficiency of capillary materials application, providing higher efficiency of iron ions removal from model solutions for real water sources of different origin compared with the traditional method of settling. The main advantage of the application of materials with capillary properties is the simplicity of implementation of the method and there is no need to use electricity and any additional reagents. The effect of various factors on the process of water deironing with the application of capillary materials was studied. It was found out that the density has a little effect on the process at an iron concentration range from 1 to 5 mg/dm3. The increase in competing ions content intensifies the process of divalent ferrous ions transition to trivalent. During the deironing of artesian water, the degree of iron removal exceeded 90 %, while the residual concentration was below the MPC.

The possibility to dispose of paper mill sludge as part of a composition of container cardboard from secondary raw materials has been investigated. The fractional composition of the sludge was studied and it was shown that the main part of the fibers is represented by small particles with a size of up to 1.2mm. Studying the processes of formation of container cardboard when using paper mill sludge showed that an increase in the consumption of fibrous-inorganic waste leads to a deterioration in the physical and mechanical properties of cardboard. However, the increase in sludge consumption does not affect the surface absorption of water during one-sided wetting. The value of these indicators is within the normal range and is 25 and 70g/m2, respectively. In addition, an increase in sludge consumption from 10 to 50% in the manufacture of cardboard leads to a decrease in the degree of fiber retention on the grid from 86.3 to 82.1%. Regularities of using strengthening additives, namely industrial cationic and anionic flocculants, as well as native corn and modified starches for the strength of cardboard and the quality of sub-grid waters, have been established. Research results show that the effect of flocculants is quite ambiguous. On the one hand, there is a clearly observed positive impact on the quality of the sub-grid waters. This is due to the reduction of their turbidity due to smaller fiber washes. Nevertheless, the positive effect on physical and mechanical parameters is minimal, and in some cases, there is a decrease in strength indicators. The greater the efficiency of keeping fine fiber on the grid when using flocculants, the lower the values of physical and mechanical indicators. In general, when using sludge in the composition of cardboard in combination with flocculants and starch, the indicators were achieved that are considered standard for waste paper container cardboard of grade KT-1 according to TU U 17.1-41085075-002:2017

This paper studies the effect of mechanical pretreatment of NPKCa-containing waste (vegetable waste VW and thickened sewage activated sludge TSAS) on biogas production and agronomic quality of the digestates. The efficiency of this process was evaluated by the yield of methane during anaerobic co-digestion with bioadditive (cheese whey), as well as the nutrients content in digestates by using an agrochemical test. It was found that with increasing comminution intensity the particle size of the substrate decreases from 50 to 16 μm which causes an increase in biogas yield by ~30%. As a result, the carbon content in the digestates decreases from 72 to 44%, whereas nutrients content increases by, %TS: N – 3.4; P – 3.7; K – 3.7; Ca – 7.6. The grinded substrate was used for anaerobic digestion with the addition of various amounts of cheese whey. Obtained digestates have a stimulating effect on the growth of barley and peas plants. In particular, digestion with 3 wt% of whey had the maximum impact on plant yield (+0.3–0.4 t ha−1 compared to control). Moreover, the combination of vigorous comminution with the addition of whey leads to a significant reduction in the fermentation duration (up to 4 times) and increases biogas production by 41%. Obtained digestates can be considered as organo-mineral fertilizers since they contain up to 43% of the total amount of NPKCa and meet the requirements for the content of heavy metals under Ukrainian legislation.

It is found that a high degree of purification from emulsified coal tar is achieved in the phenolic wastewater treatment using 88 mg/dm 3 of sodium bentonite with the addition of 8 mg/dm 3 of cationic flocculant in conditions the closest to industrial. This innovative method of phenolic wastewater treatment is cost­effective because of the low cost of bentonite. It is shown that the deposit formed during the wastewater treatment with bentonite floats to the liquid surface and can be separated by a scraper device for further utilization in construction. The process of biological treatment of phenolic wastewater in the combined aerator­clarifier unit is shown. It is determined that the optimum time for efficient phenol extraction from wastewater is 6 hours. It is experimentally proved that the use of this unit makes the biological treatment process 4 times faster giving significant economic benefits by reducing energy consumption for aeration. The flow diagram of complex wastewater purification from coal tar and phenol is developed. The use of it at coke and chemical plants will significantly increase the treatment efficiency and product profitability.